Air intake amount measurement device and engine

Abstract

An air intake amount measurement device 200 includes an intake distributor 3 distributing intake air CYL to cylinders 11, 12, 13, and 14, a temperature detector 202 detecting a temperature Ti of the intake air CYL, a pressure detector 201 for detecting a pressure Pi of intake air CL, and a computing unit 100 that computes an air intake amount mfcyl of the intake air CYL on the basis of the temperature Ti transmitted from the temperature detector 202 and the pressure Pi transmitted from the pressure detector 201. The temperature detector 202 detects the temperature Ti of the intake air CYL at a region W spanning, out of an inside of the intake distributor 3, a first branch portion 31 and a second branch portion 32.

The invention claimed is: 
     
       1. An air intake amount measurement device that measures a flow rate of intake air of an engine that has three or more inline cylinders, the air intake amount measurement device comprising:
 an intake distributor distributing the intake air to the cylinders of the engine; 
 a temperature detector detecting a temperature of the intake air; 
 a pressure detector detecting a pressure of the intake air; and 
 a computing unit that computes the flow rate on the basis of the temperature transmitted from the temperature detector and the pressure transmitted from the pressure detector, wherein 
 a longitudinal direction of the intake distributor follows a direction in which the cylinders of the engine are arrayed, 
 the intake air flows into the intake distributor from one end thereof in the longitudinal direction, and 
 the temperature detector detects the temperature of the intake air at a region spanning, out of an inside of the intake distributor, a first branch portion of the intake distributor that is connected to a first cylinder of the engine disposed at a position farthest from the one end in the longitudinal direction, and a second branch portion of the intake distributor that is connected to a second cylinder of the engine disposed at a position next farthest from the one end in the longitudinal direction after the first cylinder. 
 
     
     
       2. The air intake amount measurement device according to  claim 1 , wherein the pressure detector detects the pressure of the intake air at the region. 
     
     
       3. The air intake amount measurement device according to  claim 2 , wherein the pressure detector detects the pressure of the intake air at a position closer to the one end in the longitudinal direction as compared to the intake air of which the temperature is detected by the temperature detector. 
     
     
       4. The air intake amount measurement device according to  claim 1 , further comprising:
 an exhaust circulator circulating exhaust of the engine; and 
 a differential pressure detector detecting a differential pressure between the exhaust flowing through the exhaust circulator and the intake air flowing through the intake distributor, and transmits the differential pressure to the computing unit, wherein 
 the computing unit further computes the flow rate on the basis of the differential pressure transmitted from the differential pressure detector, and 
 the differential pressure detector detects the differential pressure on the basis of the pressure of the intake air at the region. 
 
     
     
       5. The air intake amount measurement device according to  claim 4 , wherein the differential pressure detector detects the differential pressure on the basis of the pressure of the intake air at a position closer to the one end in the longitudinal direction as compared to the intake air of which the temperature is detected by the temperature detector. 
     
     
       6. The air intake amount measurement device according to  claim 5 , wherein the differential pressure detector detects the differential pressure on the basis of the pressure of the intake air at a same position in the longitudinal direction as the intake air of which the pressure is detected by the pressure detector. 
     
     
       7. The air intake amount measurement device according to  claim 4 , wherein the differential pressure detector detects the differential pressure on the basis of the pressure of the exhaust between a cooler cooling the exhaust flowing through the exhaust circulator, and a flow rate adjustor adjusting a flow rate of the exhaust flowing through the exhaust circulator on a downstream side of the cooler. 
     
     
       8. The air intake amount measurement device according to  claim 7 , further comprising:
 a spacer provided to the exhaust circulator between the cooler and the flow rate adjustor, wherein 
 the spacer has a hole formed passing through in a direction intersecting a flow of the exhaust flowing through the exhaust circulator, and 
 the differential pressure detector detects the differential pressure on the basis of the pressure of the exhaust extracted through the hole of the spacer. 
 
     
     
       9. The air intake amount measurement device according to  claim 8 , further comprising:
 an exhaust pressure acquiring path that is connected to the spacer and the differential pressure detector, and that conveys a pressure of the exhaust extracted through the hole to the differential pressure detector, wherein 
 at least a portion of the exhaust pressure acquiring path connected to the spacer is made of metal. 
 
     
     
       10. An engine that is equipped with an air intake amount measurement device that measures a flow rate of intake air, and that has three or more inline cylinders, wherein
 the air intake amount measurement device includes
 an intake distributor distributing the intake air to the cylinders of the engine, 
 a temperature detector detecting a temperature of the intake air, 
 a pressure detector detecting a pressure of the intake air, and 
 a computing unit that computes the flow rate on the basis of the temperature transmitted from the temperature detector and the pressure transmitted from the pressure detector, 
 
 a longitudinal direction of the intake distributor follows a direction in which the cylinders of the engine are arrayed, 
 the intake air flows into the intake distributor from one end thereof in the longitudinal direction, and 
 the temperature detector detects the temperature of the intake air at a region spanning, out of an inside of the intake distributor, a first branch portion of the intake distributor that is connected to a first cylinder of the engine disposed at a position farthest from the one end in the longitudinal direction, and a second branch portion of the intake distributor that is connected to a second cylinder of the engine disposed at a position next farthest from the one end in the longitudinal direction after the first cylinder.